Core-drill.



PATENTED MAR. 26, 1907.-

R. M; DOWNIE.

GORE DRILL. APPLIOATION FILED rmagzmlsoe.

2 SHEETS-SHEET' 2.

Mayr

4 f/ m M 1 Fig. 5.

UNITED sTATEs PATENT oEEioE.

'ROBERT M. DOWNIE, OF BEAVER FALLS, PENNSYLVANIA, ASSIGNOR TO KEYSTONE DRILLER CO., OF BEAVER FALLS, PENNSYLVANIA, A OOR- PORATION OF PENNSYLVANIA.

CORE-DRILL'.

Specification of Letters Patent.v

Patented March 26, 1907.

To ,Z, wil/071i, t iitctg/ concern:

Be it known that l, ROBERT M. DowNiE, a citizen of the United States, residing at Beaver Falls, in the county of Beaver and State of Pennsylvania, have invented a new and useful CoreDrill, of which the following is a specification.

ln core-drills, particularly those of the percussion type, a number of objections are present. ln the first place the structure of the cutters is ordinarily such that they stick fast in the well, and this is due to the fact that su'liicient play has not heretofore been secured to permit them to cut a hole large enough for their necessary movement. Ann other trouble has been in providing a structure that will cut beneath the lower end of the core-barrel, and thus produce a core of small enough diameter to enter such barrel. Finally, as the drill-stem is in the form of a tube or casing the strength of the joint between the same and the cutter is limited by the thinness of the former. lt has therefore been impossible to wrench up the joints tight enough to prevent them becoming loosened and unserewed by the cutting ofthe stroke.

lt is the piincipal object to provide by this invention a novel structure which is not only effective as a core-drill, but which will eliminate the above-noted serious objections.

The referred embodiment of the invention is i lustrated in the accompanying drawings, wherein- Figure 1 is a view, partly in elevation and partly in' section, of the lower portion of a core-drill. Fig. 2 is a side elevation, on an enlarged scale, of the cutter. Fig. 3 is a bot tom plan view of said cutter. Fig. 4 is a longitudinal sectional view through the same. Fig. 5 is'a detail sectional view illustrating the stiucture when in ilse and in a well. Fig. 6 is a similar view taken at right angles to Fig. 7 is a horizontal sectional view taken substantially on line 7 7 of Fig. (3.

Similar reference-numerals designate corresponding parts in all the figures of the drawings.

ln the embodiment illustrated a portion of a reciprocatory drill-sten] is shown and is designated 8, said stem, as usual, being in the form of a tube. Within the stem 'is slidably mounted a core-receiving tube or core-barrel 9, the said barrel being of less diameter than the bore of the tubular stem, and said stem being capable of a lateral movement with respect to the barrel. A cutter 10 is carried by the lower end of the stem and comprises a tubular body 11, having an upstanding portion 12, which is eXteriorly threaded and is screwed into the lower end of the stein. The barrel 9 is slidable through the cutter-body and is of less diameter than the bore of the same, so that said cutter can swing laterally with the stern and with respect to the barrel,

Carried by the lower end of the cutterbody 11 are sets of tooth members 12 and.

13. The members of each set are located on diainetrically opposite sides of the body, and the members of the different sets have their central portions disposed substantially ninety degrees apart. Each tooth member is provi ed with one or a pluralityof cutting-teeth 14 and 15. The teeth of one set of members are inwardly inclined or set inwardly, while those on the other set of members are outwardly inclined, the tooth or teeth of each member thus being correspondingly arranged. As a result of this construction it will be observed that on two sides of the body the teeth, as 14, are outwardly set, while on the other two sides the teeth are inwardly set. The distance between the diametrically opposite inset teeth are at their cutting-points substantially the same as the diameter ofthe core-receiving barrel 9. This particular arrangement has decided advantages, for it will be apparent that at two diametrically opposite sides only will the outset teeth of tie drill touch the outer Wall of the borehole, and in like manner the inwardly-set teeth; being located on two sides only of the drill, will engage the core on but two sides. This arrangement therefore allows the lateral jostling of the drill with respect to the corebarrel, and consequently with respect to the core received therein. Thus not only will the drill-hole or well be made of greater diameter than the drill, but the core will be formed of less diameter than the bore thereof. I t is believed that this will be clear byreference to Fig. 5.

lt will be noted that when one set of outwardlyl-flared teeth-are against the outer wall of the drill-hole the other set will be spaced therefrom, and this lateral movement will also cause the lateral movement of the in- IOO ' wai-diy 1' Y i ticular construction of the teeth.

g teeth to jostle back and forth and operate beneath the lower end of the core-barrel, as shown in Fig. 6. The result is that the core will be trimmed down to the diameter of the barrel, and the latter will consequently receive the same without difliculty'. This corebarrel may be provided with va suitable clutch-ring, (shown at 16 in Fi s. 5 and 6,) so that when the drill is elevate the core'will be retained within the barrel and lifted with it. The jostling o`r lateral shifting movements thus allowed to the drill will in practice cause the same as a whole to cut a hole somewhat larger than a diameter represented by the distance between the outside -cutterpoints and a core somewhat smaller than a diameter represented by the distance between the inside cutter-points, thus affording clearance and preventing sticking. Moreover, as the lateral play is controlled by the internal bore of the cutter-head as a whole the diameter of the core can likewise be controlled. Said core can consequently be made small enough to enter the core-barrel, as theside shifting will permit the inner teeth to operate beneath the lower end of said barrel.

Another advantage is gained by the arlt wi be observed that each tooth member' is separated from the'adjacent tooth member by a deep notch 17, and the teeth on each' member are formed by an intermediate notch 18 of less depth than the notches 17. The righthand edges 20 of the teethV are substantially vertical, while the left-hand edges 21 are inclined, and it is to be observed that the pitch of the edges 21 is opposite to the pitch of the screw-threads by which the cutter is held in the casing. ter points or teeth strike the rock they will tend to advance or revolve the cutter-head to the right, and the inertia of the casing and the parts carried thereby will consequently tend to cause a relative rotation of the cutter, so as to effect the tightening movement at the joint, thus avoiding the danger of the parts unscrewing.

It will be observed that the inclined sides of all of the teeth'have an inclination in the same rotative direction and that the effect-of the inclined sides of all the teeth is cumulative. of the vertical sides of the teeth .is dislod ed or chiseled away, leaving the material enea-th the, inclined sides to form aseries of inclined slides. Thus it will be seen that the cutter-points at the instant of impact with the bottom of the bore-hole will be given a.

sort of corkscrew motion, enabling the points of the inwardly-set teeth 15 to more eiiectively trim or out the core down to asize that will enter the core-barrel. The outwardlyset teeth 14 as a matter of factdo nearly all of the cutting, and consequently the princiwardly-set, vpal As a result every time the cut- In operation the material from in front lpart of the above corkscrew effect is due to t e inclination of the outwardly-set teeth 14, and it can be easily understood that thev outwardly-set teeth operating at one side of the bore-hole may have more tendency. to rotate or slide than those at the diametrically opposite side, and at the instant of impact if one of the sets of outwardly-set teeth should slide forward faster or farther than those at the opposite side of thebore-hole the effect will be to carry one of the roups of inwardlyset teeth under the end of the core-barrel to more effectually trim the core down. Hence the inclined form of teeth shown clearly in Figs. 1, 2, 3, and 4, together with their distribution, forms an important part of this invention. y

To fully understand the operation of the drill, it must be remembered that a reciprocatory or percussion drill operated by a cable will naturally j ostle upon striking the rock or bottom of the drill-hole, and as a consequence .the hole is of greater diameter than the drill.

same after each lstroke with high and flow places of irregular height and depth. Then in the great majority of instances at the next descent, having been sli htly rotated by the action hereinafter descri`- ed, one or the other of the outside sets of cutter-teeth will'strike a high place an instant before the corresponding set at the opposite side will strike.

The

downward force of the drill will throw'the striking-teeth forward, while at the same time the inertia of the drill will momentarily .hold the said opposite teeth against a like forward movement. Now owing to the slight clearance outside the outer cutter-teeth, the set which has struck the high place, as above, will describe a portion of a circle whosev center for the instant is the corresponding opposite set. This swinging or rotary movement, as will be evident,` will car one of the inner sets of teeth 15 beneath t e core-barrel, so that it will engage and trim down the core; but as the said swinging movement of they drill will be limited by the core-barrel the trimming action will just be sufficient to permit the core to pass into said barrel. At the next stroke the swinging movement above described may be in an opposite direction. As a matter of fact there will be only a very small lpart of a circle (iive to ten de rees) described by the forward or lateral motion of the teeth 14 at each stroke; but itis abundantly suflicient to carry the inside cutterteeth 15 under the end of the core-barrel and cause themV to trim the core down small enough to enter the barrel. These motions are what are termed the jostle, and it is this which makes the tool as a whole successfully operative. In this connection it is to be noted that the rear edges of the teeth are set at an angle of over fifty degrees from the erpendicular. This is of great-importance,

or if disposed at much less of an angle there would be no forward movement, and if the teeth were not broken by the impact each would in all probability dig a hole for itself, and the desired results would not be obtained. The arrangement of the teeth ninety degrees apart, or, in other words, the placing of the corresponding teeth one hundred and eighty Y degrees apart, is of great importance. It',

for instance, there were three sets of outerv teeth at one hundred and twenty degrees apart, or a greater number at a less number o degrees apart, they would so brace and counteract each other that the drill as a whole would be very apt to at all times remain substantially concentric to the borehole, and the necessary lateral swing could not be obtained.

From the foregoing it is thought that the construction, operation, and many advantages o the herein-described invention will be apparent to those skilled in the art without further description, and it will be understood that various changes in the size, shape, proportion, and 'minor details of construction may be resorted to without departing -from the spirit or sacrificing any ofthe advantages of the invention. Thus the drawings herewith show a total of eight cutterpoints arranged in four groups of two each, and while in practice this is found to be the best number of cutter-points yet it will be observed that each of the four groups of teeth may consist of one, two, three, or more, cutter-points, and also it may be observed that the cutter-points or some portion of them can be formed with chisel edges at right angles to those shown in the' drawings, and indeed in some particular formationsft'his latter shape of cutter-point is better.

All of the above variations can be made without departing in the least from the spirit of the invention.

I-Iaving thus fully described my invention, what I claim as new, and desire to ,secure by Letters Patent, is-

1. A percussion or reciprocatory core-cutter comprising a body having a plurality of depending tooth members, the members of each set being diametrically opposite,` and the members of the different sets being disposed on the body at points substantially ninety degrees apart, the tooth members of one set of members extending inwardly and those of the other set extending outwardly.

2. A percussion or reciprocatory core-cutter comprising a body having a plurality of' depending tooth members, the members of each set bein0r diametrically opposite and the members of the different sets being disposed ment w1 i r ec t barrel, and a per- /cussion-cutter carried by the ower end of the on the body at points substantially ninety degrees apart, the tooth members of one set of members extending inwardly and those of the other set extending outwardly, said tooth members each having a group of teeth.

3. A percussion or reciprocatory core-cutter comprising a tubular body having dependino tooth members located at points substantialy ninety degrees apart, said members being alternately set inwardly and outwardly.

4. In al percussion or reoiproeatory coredrill, the combination with a core-receiving barrel, of a drill surrounding the same and laterally movable with respect thereto, and core-trimming teeth carried by the lower end of the drill and having cutting edges at their lower ends that operate beneath the corebarrel upon the lateral movement of the drill.

5. In a percussion or reciprocatgry coredrill, the combination with a core-receiving barrel, of a drill surrounding the same and laterallyT movable with respect thereto, and inwardly set pointed core-trimming teeth carried by the lower end of the drill and having cutting edges at their lower ends that o'perate beneath the barrel, tlre inward movement of the teeth being limitedby the corebarrel.

6. A percussion or reciprocatory core-cutter, comprising a body having a plurality of depending sets of tooth members, the members of each set being diametrically opposite, and the members ofthe different sets having their central portions disposed substantially ninety degrees apart, the tooth members of one set extending inwardly and' those of the other set extending outwardly, said tooth members each having a-plurality of teeth, and the teeth of'each member extending in rthe same direction.

7. A percussion or reciprocatory core-cuta core-barrel member slidably mounted therein, said stem b stem and having. inwardly-extending teeth that are capable of lateral movementwitn mmm e ower end lie o said barrel.

8. The combination with a tubular reciprocatory stem, of a core-barrel slidably mounted therein, said stem being capable of a lateral movement with respect to the barrel, and a percussion-cutter carried by the lower end of the stem andincluding a tubular body having diametrically opposite inwardly-extending teeth that are capable of lateral movement with the stem and with respect to the barrel to positions beneath the lower end of the core-barrel to trim the core beneath said barrel.

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. ter, comprising a tubular reciprocatory stem,

9. The combination wi th-a tubular reciprocatory stem, of a core-barrel slidably mounted therein, said core-barrel being of less diameter than the bore of the stem, said stem thus being capable of a lateral movement with respect to the barrel, and a percussion-cutter carried by the lower end of the casing and including a tubular body having diametrically opposite tooth members, each member including aplurality of adjacent 'teeth inclined inwardly and capable of lateral movement with the stem to positions beneath the lower end of the core-barrel to trim the core beneath the same.

10. The combination with a tubular reciprocatory stem, of a core-barrel slidably mounted therein, said stem being capable of a lateral movement with respect to the barrel, and a percussion-cutter carried by the lower end of the stem and comprising a body having a plurality of depending sets of tooth members, the members of each set being diametrically opposite and the members of the different sets having their central portions disposed substantially ninety degrees apart, the tooth members of one set extending inwardly and being capable of a lateral movement with the stem and with respect to the barrel to positions beneath the lower end of the core-barrel, the members of the other set extending outwardly.

1 1. The combination with a stem, of a cutter threaded on the stem and having depending teeth, said teeth having substantially vertical sides and inclined sides, the latter sides beingr inclined in an opposite direction to the threads of the joints.

12. The combination with a reciprocatory tubular stem, of a cutter comprising a tubular body threaded on the stem and having depending inwardly and outwzgrrdly extending teeth, said teeth having substantially vertical sides, and inclined sides, the latter sides being inclined in an opposite direction to the'threzlds, and a core-barrel slidably mounted in the stem, said stem and teeth being capable of a lateral movement with respect to the barrel.

13. In a percussion or reciprocatory coredrill, the combination with a core-barrel, ot' a reciprocatory drill-stem surrounding the same and laterally movable with respect thereto, cutting-teeth carried by the lower end of the stem, and inset core-trimming teeth also carried by the lower end of the stem and swingingbeneath the core-barrel on the lateral movement of the stem.

14. In a percussion or reciprocatory core- 15. In a percussion or reciprocatory coredrill, the combination with a core-barrel, of a reciprocatory drill-stem surrounding the Same and laterally movable with respect thereto, outside cutting-teeth carried by diametrically opposite portions of the lower end of the stem, and inset core-trimming teeth disposed between the cutting-teeth and also carried by the lower end of the stem, said inset teeth swinging beneath the core-barrel on the lateral movement of the stem.

16. In a percussion or reciprocatory coredrill, the combination with a core-receiving barrel, of a reciprocatory stem surrounding the same and capable of lateral movement with respect thereto, and teeth rigidly carried by the lower end of the stem and operating beneath the core-barret to trim a core to pass into said barrel.

17. In a percussion or reciprocatory coredrill, the combination with a core-receiving barrel, of a reciprocatory stem surrounding the same and capable of lateral movement with respect thereto, outstanding teeth rigidly carried by the lower end of the stem, and inset teeth rigidly carried by the lower end of the stem and operating beneath the core-barrel to trim a core to pass into said barrel.

18. In a percussion or reciprocatory coredrill, the combination with a core-barrel, of a reciprocatory drill-stem surrounding the same and laterally movable with respect thereto, outside cutting-teeth carried by diametrically opposite portions of the lower end of the stem7 said teeth having rear edges that are disposed at an inclination to produce a rotary movement of said cutter upon its impact with the bottom of the bore-hole, and inset core-trimming teeth carried by the lower end of the stem and swinging beneath the core-barrel on the lateral movement of said stem.

In testimony that I claim the foregoing asV my own I have hereto aiixed my signature in the presence of two Witnesses.

ROBERT M. DowNiE.

IVitnesses:

R. G. FORBES, F. W. RANsoM.

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